Retractable anvil stapling machine



w. scHAFRoTH ETAL 2,722,001

RETRACTABLE ANVIL STAPLING MACHINE Filed Oct. 5, 1950 5 Sheets-Sheet l INVENTORS JOHN H. MOTT W RNER SCHAFROTH Hz? @Mar/1 e y Nov. 1, 1955 w. scHAFRoTH ETAL 2,722,001

RETRACTABLE ANvIL STAPLING MACHINE Filed Oct. 3, 1950 5 Sheets-Sheet 2 INVENTORS JOHN H. M077' l WERNER .SCHAFROTH BY M Nov. 1, 1955 Filed Oct. 5 1950 W. SCHAFROTH ET AL RETRACTABLE ANVII.. STAPLING MACHINE 5 Sheets-Sheet 3 INVENTORS JOHN H. MOT WERNFR SCHAFROTH Nov- 1, 195.5 w. scHAFRoTH ET AL 2,722,001

RETRACTABLE ANVIL STAPLING MACHINE 5 Sheets-Sheet 4 Filed Oct. I5, 1950 Nov. 1, 1955 w. scHAFRoTH ET AL 2,722,001

RETRACTABLE ANVIL STAPLING MACHINE Filed oct. 5, 195o 5 Sheets-Sheet 5 the staple driving blade.

United States RETRACTABLE ANVIL STA-PLING MACHINE Werner Schafroth, Havertown, and .lohn H. Mott, Wayne, Pa., assignors to International Staple and Machine Company, Pittsburgh, Pa., a corporation of Pennsylvania Application October 3, 1950, Serial No. 188,117

8 Claims. (Ci. 1-49) The present invention has to do with stapling machines :and is concerned primarily with stapling machines of the retractable anvil type.

The lpresent invention provides a retractable anvil stapling machine which operates on a principle which is novel in this iield and because of this radical departure over the known principles the machine is lighter in weight and cheaper in cost than comparable prior art machines and includes other features which are desirable from the viewpoint of practical utility.

As the name implies, a retractable anvil stapling machine is a machine which includes anvils that pierce the material being stapled and which cooperate with the legs ofthe staple to clinch them. After the clinching operation the anvils are retracted. Such stapli-ng machines are adapted for use where access maybe had to only one face of the material being stapled. A good example of this :is the closing of the liaps of a corrugated carton.

The lrst retractable anvil stapling v'machines operated on the .principle of lirst driving the anvils into clinching vposition and then driving the staples onto the anvils. In certain later developments it has been proposed to tirst 4 drive `the staples and then `drive the anvils to clinch the staples. ln either case there kare two operating strokes .that are more or less independent and it has been necessary to provide for these separate operating motions in the machine.k In some instances two separate operating strokes have been .used and in others there has been one main operating stroke that lis broken up into two components with `certain lost motion provided therebetween. It has also been necessary to use cams, cam plates, `or similar instrument-akties in providing Vfor the Vproper operation of the anvils and :the corelation of this operation to the driving of fthe staples. f Y With the foregoing conditions in mind, the present invention has in View as its 'foremost objective 'the provision of -a retractable anvil stapling machine in which the .anvils and the staple are driven at the .same Vtime and by a-single Operating stroke of the machine. With -this operation the legs of the staple pierce the material being stapt-ed While 'the anvils fiirst penetrate the material ion the `outer sides of the legs. The anvils :then snor/e over into engagement with the staple legs -to cause their clinching during the final stages of the driving stroke.

Another highly important object of s-the invention is to provide a retractable anvil 'stapling machine in :which all cams, :ca-m ,plates, or comparable instrumentalities are .eliminated This Vobject is achieved by the principle of Operation above outlined which is carried out in conjunction with anvils that are pivotally mounted on fixed axes in the machine. The anvils operate with `a `rotary motion and are connected by links with a plunger which carries Thus, 4all ,lost Amotion .devices 4are eliminated as well as cams, earn plates, or other mechanisms in which `parts slide V,relative to one `another -and cause wear.

A good idea of the practical advantages which are de- ;fi'ved from a retractable anvil stapling machine which Patent operates on this novel principle may be gained by considering the fact that a manually operable machine made in accordance with the latest approved practices in this field which is pnt out by the assignee of this application weighs about fourteen and one-half pounds. This machine is effective to drive the heavy duty staples which are ordinarily employed in closing cartons. A machine having the same operating capacity may be made [ollowing the principles of this invention and will weigh about four pounds and four ounces. Moreover, it is made at a cost of about one-third the cost of the heavier machine. Not only is there this great saving in the initial cost but when it is considered that these machines are intended to be manually handled by operators, many of whom are girls, the importance of the reduction in weight cannot be overestimated.

Inst about every stapling machine, whether of the retractable anvil or other type, must include a magazine which feeds the staples into driving position. An important obiect ot' the invention lies in the provision of a new and improved magazine that is particularly adapted for use with a retractable anvil machine of the type aforesaid.

In accordance with the present invention the magazine is detachably assembled in the machne but is springloaded with the force yof the spring maintaining the assembled relation. The magazine carries a supply of staples in the form of a strip of staples which is fed by additional spring means. An important feature of the invention resides in the fact that Vthe spring-loaded clip which holds the magazine assembled cannot be released until the spring-feeding mechanism for the strip of staples has been removed. This guards against accidental release of the magazine.

Another highly important object of the invention is to provide a retractable anvil stapling machine in which the magazine feeds the staple which is to be driven directly into driving position. During the feeding operation the staple does not assume any intermediate or temporary position and all caps or retaining devices, `either sliding or liXed, which, in now known machines, hold the staple in an intermediate position are eliminated. With this arrangement substantially all possibility of bad jamming is eliminated and should a staple be malformed upon one operation the machine may be cleared by a subsequent operation without the necessity of disassembling the machine.

From the very nature of their intended use retractable anvil stapling machines are used on different materials having different thicknesses. in view of this condition the machines must be susceptible of adjustment to vary the extent of penetration of the anvils. The nonI known machines include this feature of adjustment but these machines are generally characterized as including a false bottom which is pivotally vmounted on the frame and which 4is swung on its pivotal mounting to achieve the adjustment. With this arrangement it is obvious that the machine is always tilted at a slight angle.

Another important object of this invention is to provide, in a retractable anvilstapling machine of Vthe type indicated, a new and improved penetration control. This control is highly simplified and is carried out by providing for the adjustment of the entire operating mech- Yanism relative to 'the frame. Thus, all false b ottoms are Ventirely eliminated and the machine assumes an accurately upright position in which the staples are driven overa path that is normal to the material being stapled.

Another highly important object of the present invention is to provide, in a retractable anvil stapling machine .of the character aforesaid, mechanism for adjusting the vamount ,of compression which is achieved by the anvils andthe staple driving blade. The extent of this compression depends v`on @the .length of the operating stroke.

Thus, during the iinal stages of this stroke the anvils move toward the blade and the further the movement is continued the more will be the compression.

In accordance with the present invention a screw is adjustably mounted in the frame and has a free end which functions as a stop or abutment in conjunction with the mechanism that drives the plunger to which the anvils and blade are connected. By rotating this screw to adjust the position of its free end the length of the operating stroke may be varied to achieve a desired degree in the compression.

From the aspect of practical utility it is highly important that retractable anvil stapling machines of the type with which this invention is concerned be susceptible of easy disassembly and assembly in the hands of the user. In the machine provided by this invention all complex parts are entirely eliminated and the number of moving parts has been substantially reduced as compared to machines heretofore known. The result is a highly simplified machine which includes only one screw in its entire makeup. This screw is the adjusting screw mentioned above. Moreover, the machine may be entirel dismantled by using a hammer and a tool in the nature of a punch. A nail will till all the requirements of this punch. When it is considered that the machines heretofore known required special tools for their servicing, the importance of this advantage becomes apparent.

Another object of the invention is to provide a retractable anvil stapling machine of the type indicated which includes a frame, the several parts of which are pressed from sheet metal and welded together. This frame is assembled on the main standard of the machine and the latter is hollowed out at appropriate points to achieve the quality of lightness in a complete machine.

When the large number of staples which are intended to be driven by one of these machines is considered, it is evident that it is desirable to reduce to as great an extent as possible all relative movement between the staples and the retractable anvils. The greater such movement the greater will be the wear on the anvils. The present invention provides for driving the anvils at the same time that the staple is driven and an important object of this invention is to so correlate these movements so as to reduce to an absolute minimum this relative movement between the anvils and the staple.

Various other more detailed objects and advantages of the invention such as arise in connection with carrying out the above noted ideas in a practical embodiment will, in part become apparent, and in part be hereinafter stated as the description of the invention proceeds.

The invention therefore comprises a retractable anvil stapling machine in which the anvils are driven simultaneously with the staple through the medium of actuating mechanism comprising xed pivotal mountings for the anvils and operating links which are connected to a plunger carrying the staple driving blade. The invention also embraces certain improvements in the magazine, the penetration control, the adjustmentof the compression between the anvils and the staple driving blade, as well as other features which provide for a highly simplied machine.

For a full and more complete understanding of the invention, reference may be had to the following description and accompanying drawings wherein:

Figure 1 is a side view taken generally as a vertical section although on different planes through a retractable anvil stapling machine designed in accordance with the precepts of this invention; v

Figure 2 is a fragmentary showing taken as a bottom plan view of the forward or operating end of the machine;

Figure 3 is a detailed section through the casing being taken about on the plane represented by the line 3 3 of Figure 2 showing the plunger, retractable anvils, operating hnks between the two, and the staple driving blade in elevation and in the position which the parts assume at the beginning of an operating stroke;

Figure 4 is a view similar to Figure 3 showing the relative position of the parts upon the completion of an operating stroke;

Figure 5 is a detailed perspective of the plunger and staple driving blade carried thereby;

Figure 6 is a top plan view of one of the retractable anvils per se;

Figure 7 is a view in elevation looking at the machine from the rear with the magazine removed;

Figure 8 is a View in end elevation of the magazine;

Figure 9 is a detailed view looking from the inside at one of the side frame parts showing the spring-loaded clip which biases the magazine;

Figure 10 is a detailed perspective with parts broken away and shown in section of the inner magazine part;

Figure 11 is a similar view of the outer magazine part;

Figure 12 is a detailed perspective of the staple pusher;

Figure 13 is a view in front elevation of the machine with a portion of the operating lever broken away;

Figure 14 is another view in front elevation with certain parts of the penetration control omitted;

Figure 15 is a detailed perspective of one element of the penetration control.

Figure 16 is another detailed perspective of another element of the penetration control.

Figure 17 is a horizontal section through the machine looking downwardly and taken about on the plane represented by the line 17-17 of Figure 1; and

Figure 18 is a vertical section through the magazine looking inwardly towards the machine and taken substantially on line 18-18 of Fig. 1.

Referring now to the drawings and irst more particularly to Figure l, the retractable anvil stapling machine of this invention is shown as including a main standard 10. This standard 10 is preferably molded in the shape desired with certain surfaces subsequently machined. At the top the standard 10 is formed with a pair of spaced ears 11 through which extend aligned openings 12 for a purpose to be later described.

Below the ears 11 the standard 10 carries a hollowedout knob 13 which is formed as an integral part of the standard 10. The inner or rear face of the standard 10 is designated 14 and opening onto this face is a recess 15. A threaded passageway 16 extends through the thickened portion of the standard 10 and communicates with the recess 15, the latter being in elfect a counterbore of the passageway 16. The knob 13 is formed with an opening 17 that is in alignment with the passageway 16 and counterbore 15. An adjusting screw 18 has a head 19 that is formed with a tool receiving kerf 20 and which head is received in the opening 17. The main body portion of the screw 18 is screwed into the passageway 16 and projects through the counterbore 15. This screw 18 has a free end at 21 which is adapted to serve as an abutment as will be later described.

The front face of the standard 10 is designated 22 and this face may be formed with a large recess 23 which is provided for the purpose of eliminating unnecessary metal. Below this recess 23 the standard 10 is formed with a transversely extending groove 24 which opens into the front face 22. Adjacent to its bottom edge the standard 10 is formed with two openings 25 which accommodate the pivot pins for the anvils as will be later described. Covering the rear face 14 of the standard 10 and for all effective purposes constituting a part thereof is a wear plate 26 while a front frame wall 27 covers the front face 22.

As is brought out more clearly in Figure 2 this front frame wall 27 carries side flanges 28 which encompass the side edges of the standard 10. Extending outwardly from the flanges 28 are side wings 29.

Anvil guards designated 30 include front wall sections 3]. which overlap the wings 29 and flanges 32 which -overlie @the flanges 28. .':Fhe anvil guards .30 also -in- 'clude rear wall .sections 33 which :terminate linizilanges 34.

A rear frame wall is designated .35 :and i's shown lmore clearly in Figure 7 although .the lower edges also appear .in Figure 2. This ,rear frame `wa1l35 .is 4formed with a vertical slot 36 (Figure 7) the edges 'of'which fare d'ened by the rearwardly turned iiang'es 37. Integrally joined to this rear frame wall :are side walls.38 (see .Figure 1.). These side walls 38 extend to the standard 10 and cooperate therewith rin providing a chamber which slidingly receives a plunger `to be later described.

Side frame sections 3.91have upper'bevel'ed ledges in the `form of :inturned arrges :40 and straight bottom edges in `the form 'of inturned flanges 41. 'The forward .ends 'of these side frame sections are received between the flanges 34 of the anvil guards .30 (Figure 2) to which they `are secured as by welding. 1Iiheendfedgesabut the rear-iframe wall 35. Crosspieces shown 'at l42 extend across the Vside iframe section -39 and preferably 4:have their'ends welded to the upperffacesof 'the iianges 4-1. It :is evident that the .e

trame of the .machine .is made up 'of liront wall 27 vv`and .flanges formed lintegrally therewith, the 'anvil -gu'ards 30 and .iianges 'carried thereby, andthe rear w'all 3S together with the vside Wall sections 39 xcarried thereby.

A plunger is shown in detail in Figure 5 and referred f l)` The plunger .Peomprise's fa block 43 .having a slot-44 opening onto its upper edge. '.Ihis slot 44 extends between the front and rear faces 'of the block 43. 'The block 43 is formed with another slot v45 which opens onto its bottom edge 'and which extends betweenthe A'side -faces of the block.

The block 43 `is formed `'with .aligned passages 46 on opposite sides of the slot 44. .I't is also `formed with two `pairs of aligned :openings `470m opposite sides of fthe slot 45. The rear face of the plunger block f43 is 'designated 48 and is cut away vas .indicated at '49 -lto accommodate a staple .driving blade 50 lso that when this blade is assembled in the 'manner illustrated its :exposed face will be ilush with the face 48. ARivets shown yat 51 fsecure the staple driving blade 50 to the block 43.

An operating lever is-d'esignated 52 and is illustrated in the lever 52 on the standard 10. The end `oftthe lever `52 .remote from this pivotal mounting .carries a handle extension 55.

Extending downwardly from the ,lever.52 are .a pair of ears 56 between which is received one end of a plunger operating link 57. A pivotpin 58 extends throughraligned openings in this end of the 4link 5.7 and the ears 56. VThe other or lower end .of the link 57 is received'in the slot 44 of the .plunger block 43 and is formed with -anopening in alignment with the passages 46. A pivot pin .59 passes through these aligned openings and serves to operatively .connect the link 57 to the -plunger block 43.

A pair of retractable anvils `are included in .the machine. Each of these anvils is referred to in its entirety by the reference charactei A 'and fone .of them is 'shown in ldetail in Figure 6. Each anvil A includes a fmain 'body portion in the form of a straight lever arm `60 (Figure 4) and a `curved anvil section 61 vvhaving an anvil surface 62 termivnatingin a point 63.

The straight lever arm 60 of each anvil A is formed `with an opening 64 vwhich is in alignment `with one of the openingsZS (Figure l) in the standard 10. A `pivotpin 65 passes Athrough these aligned openings and serves to pivotally mount that anvil A .on a xed axis. -The end `of the straight lever arm 60 remotefrom .thisopening 64 6 is tor-med with a `'slot 66 and with alignedpassages mi Qppositesidesof the slot 66.

A pair of anvil operatingtlinks are designated `68. Each link A68 has its Vupper end received .in the slot 4S :of the .plunger block 43 and has an opening in alignment-with one `set of the passa-ges 47. Apivotpin 69 passes through these aligned openings and serves to rpivotally -connect that end of Vthe lever 68 to Ythe plunger block 43. 'The other or lower end of each lever 68 is received ina slot 66 of one of the .anvils .A andfhas lanopening .in alignment with the opening 67. Another pivot pin 70 -passels through these laligned openings and pivotally connects thatsend 4of the .lever to the anvil.

Briefly :summing .-up the'operati'on of the plunger P and anvils A, it will be noted that as the handle 55 .is 4depressed downwardly the link 57 transmits -this motion to the vplunger P to Ycause the downward .movement thereof. .As the plunger P moves downwardly it carries 'with it `fthe staple driving blade Si) and at the same time 'the ilinks 68 cause the anvils A to rotate on the pivot pins :'65 as yfixed axes.

The magazine `is referred :to .in .its entirety by the reference character M 'and is shown assembled in Figure `8. 'The magazine comprises an inner chan-nel shaped meinber 7l which is shown in detail in :Figure 1-0. 'This :inner member 7:1.carries .a wear pla-te 572 atits finner end ahdits outer end has an end wall 73 (see Figure 1) formed with 4a slot 74 (Figure 1Y0). The magazine M also includes an vouter 'channel shaped member 575 having side walls .76 which terminate 4at .their upper ends fin inturned flanges 4'77'. Struck lfrom these walls 76 'are 'outwardly'extendi-ng Vtabs 7.8 .for a Vpur-pose to be later described. The inner Vends .of these :walls .76earry abutment blocks 7.9, the pu'r- ,pose .of which .will `later .become apparent.

he channel member 7,1 -is assembled within the yinem- .ber 7,5 and the two weldedrtogether. .in their assembled vrelation the side wal-1s of the member 771 are spaced `,iinwardly from the side Walls 76. .Astrip ofstaplesisshow'n .in broken lines in Figure l andfdesignated 80. hestaple .at the rear end of this strip is shown in Figure 8. It will `be secnthat vthe Aback yof the staple has its ends disposed beneath the llanges f77 of the Vouter magazine member 7,5 with .the legs received between the side `walls of the .inner member 71 .and .the side walls 76 of the .outer magazine member.

A staple pusher 31 .is shown in -detail in Figure 12. .It is `of U-shaped formation .and assumes the `same position in the `maga/zine as vdoes 4the `strip of staples 80. A block 82 is secured to the .underface fof the staple pusher 81. A rod 83 is .conneetedto-this bloek82. VAspring retaining handle 84 is formed .witha bore which zreceives the other end of the .rod S3 .together with an expansion coil spring 85 which surrounds .the rod. One end of this spring :85 bears against theblock .82and the other against-the handle 84. The innerfendof the handle i84 isenlarged to provide shoulders which engagethe .end walls 73 onoppositesides of the slot 74. Thus, with the .handle so assembled 'the spring 8,5 will urge .the staple lpusher 81 inwardly against the strip of staples Siiptofeed .the latter'to the machine.

The staple pusher 81 together with therod 8:3 land handle 84 and spring-.85.may-be removed as a `unit fbysi'n'iply raising thehandle 84 vout of the fslot 74. This requires an initial inward .movement `on the part 'of the handle to clear ,the latter from .the ti-anges has `shown Vat 86 which are formed vas a ,part tof -the end .wall 73.

A tab 87is struckiromeach .fside frame fsection 39 :and bent inwardlyand upwardly to provide a springanchor, this being clearly shown in .Figure 9. Another .tab 858 is struck fromeach side wall lsection `39 and bent inwardly and downwardly'to provide a fulcrum or `.pivot point. -A retaining tab 89 has -integrally Aformed therewith a v'ange 90 that Yis welded to .the inner face of `a Fside frame Vsection 39. There .is one of these retainingtabs 89 ffor each side frame section. Y

A Spring-loaded clipis designated 91. 'Thiselip'eomprises a pair of side walls 92, each of which is formed with a slot at 93 which receives one of the fulcrum tabs 88. Above this slot 93 there is a spring anchor 94. A pair of springs 95 are included in the magazine for the purpose of spring-loading the clip 91. Each spring 95 has one end anchored to one of the tabs 87 and its other end to the spring anchor 94. The tendency of the springs 95 is to rotate the clips 91 about the outer edges of the tabs 88 as fulcrums.

Extending between the walls 92 of the clip 91 is a bar 96 which is adapted to be engaged by the finger of an operator to depress the clip for a purpose to be described below. Each of the walls 91 is formed with a shoulder at 97 which is adapted to engage one of the tabs 78 in the outer magazine part 75.

The rear frame wall 35 (Figure 7) is formed with an opening 98 through which staples are adapted to pass as they are fed into the path of the blade 50. The upper edge of this opening 98 is defined by the flange 99 as shown in Figure 1.

The side edges of this opening 98 are cut away a short distance below this flange 99 and formed with anges represented at 100 (Fig. 2) to receive the inner ends of the side walls 76 of the magazine part 75. With these inner ends so received the abutment blocks 79 engage the frame wall 35 to limit inward movement of the magazine.

In assembling the magazine M in the machine, the

magazine is first inserted through the back of the side frame members 39 and advanced until the walls 76 of the magazine M enter between the fianges 100 (Fig. 2). At the same time the bottom of the magazine must be pressed down against the clip 91 to rotate it against the action of the springs 95 (Fig. 9) to permit the tabs 78 (Fig. 11) on the magazine M to be lowered below the tabs 89 (Fig. l) on the sides 39 of the frame member. As the tabs 78 pass beyond the shoulders 97 on the clip 91, the clip is rotated counterclockwise by the action of the springs 95 to place the shoulders 97 behind the tabs 78 to lock the magazine M in place, and at the same time urge it inwardly of the frame to cause the abutment block 79 on the magazine to be urged into engagement with the flange 100, as shown in Fig. 2. To unlock the magazine M the operator need merely press downwardly on the bar 96 through openings formed in the inner channel member 71 and the outer channel member 71, clearly shown in Fig. 1, and as described above as extending between the walls 92 of the clip 91, withdrawing the shoulders 97 of the clip 91 from behind the tabs 78, wherein said tabs may be withdrawn from below the tabs 89 on the sides 39 of the frame member.

After the magazine has been so assembled the staple pusher 81 together with its associated instrumentalities are assembled in the magazine in the manner above described. When so positioned the rod 83 and spring 85 thereabout act as an effective guard to prevent accidental displacement of the clip 91. It is only by removing the staple pusher and its associated parts that access may be had to the bar 96 to depress the clip 91 and thereby remove the magazine.

The front casing wall 27 is formed with a circular opening 101 (see Figure 1) the center of which is above the horizontal midline of the groove 24 of standard 10. A circular casing 102 is secured to the outer face of the wall 27 about the opening 101 and concentric therewith. This casing 102 has an inturned circular flange 103.

A disc 104 is snugly and rotatably received in the casing 102 and projects through the opening 101 so that the inner face engages the front face of the standard 10. This disc 104 is formed with a slot 105 (Figure l5) and a diametric passageway 106. A block 107 is slidably received in the groove 24 of the standard 10. This block 107 is formed with an opening 108 that is located substantially along the midline of the slot. An adjusting lever is designated 109. At one end this lever carries an inwardly extending arm 110 which is formed with a loop 111 that defines a circular opening 112. The free end of this arm 110 is designated 113 and is adapted to be received in the opening 108 in the block 107.

The front frame Wall 27 is formed with a plurality of openings 114 which are arranged in an arc concentric with the disc 104. The lever 109 has an inturned end 115 which is adapted to be received in any of these openings.

The circular casing 102 is formed with diametrically aligned openings 116 in its cylindrical wall. After the loop 111 of the adjusting lever 109 has been positioned in the slot 105 so that the opening 112 is in alignment with the passage 106 the latter passage may also be brought into alignment with the openings 116. In this position a pin shown at 117 may be inserted to lock the loop 111 in position in the disc 104. After this assembled relation has been achieved the disc may be rotated whereupon the passage 106 and pin 117 come out of alignment with the openings 116. Hence, the pin 117 is held in position by the circular wall of the casing 102. The normal range of adjustment is indicated by the length of the arc over which the openings 114 are arranged. Over this range of adjustment the pin 117 is held assembled in the casing.

It is evident that by rotating the lever 109 the disc 104 is rotated. However, due to the eccentric or off-center relation of this disc, with respect to the opening 108, such movement will cause a raising or lowering of the standard 10, relative to the frame. This adjustment of the standard 10 controls the extent of penetration of the curved anvil sections 61, inasmuch as the said anvils are pivotally fixed to the standard 10 by pins 65. Thus, any adjustment of the standard 10 effects an adjustment of the anvils, and the amount that the anvils penetrate the material depends upon their position relative to the base of the frame. Accordingly, the lower the standard 10 relative to the frame the greater the penetration of the anvil sections 61.

It is evident that downward movement of the lever 52 is limited by the free end 21 of the adjusting screw 18. Thus, by adjusting the screw 18 the extent of the operating stroke may be varied to achieve a desired degree of compression.

Operation While the operation of the machine is believed to be obvious from the description of the parts given, it may be briefly outlined by noting that the adjusting screw 18 is first availed of to provide the amount of compression desired for the particular material being stapled and the lever 109 employed to give the required amount of penetration.

With the magazine M assembled in the manner illustrated in Figure 1, the staple pusher 81 will force the staple at the innermost end of the strip of staples 80 into position beneath the staple driving blade 50. The operator now avails of the handle 55 to depress the lever 52 by swinging it about the pivot pin 54 as an axis. This motion is transmitted through the link 57 to the plunger P. As the block 43 of the assembly moves downwardly the staple driving blade 50 is correspondingly moved to pick up the staple positioned therebeneath and drive it through the material being stapled. At the same time the link 68 causes the anvils A to be rotated about the fixed pivots 65 which cause the curved anvil sections 61 to penetrate the material. As the anvils so penetrate they move inwardly into engagement with the legs of the staple and thereby move these staple legs into clinched position depicted in Figure 4.

The handle 55 is then retracted into its upward position in which it will normally be held by a spring-biased pin 118 that is received in the socket formed in the upper edge of the standard 10.

While a preferred specitic embodiment of the invention is hereinbefore set forth, it is to be clearly understood 9 that the invention is not to be limited to the exact constructions, mechanisms, and devices illustrated and described because various modiications of these details may be provided in putting the invention into practice within the purview of the appended claims.

What is claimed is:

1. In a retractable anvil stapling machine, a frame and operating mechanism supported by said frame, said operating mechanism comprising a standard mounted within said frame and cooperating therewith to provide a chamber, a plunger slidably mounted in said chamber, a staple driving blade carried by said plunger, a pair of retractable anvils each of which is pivotally mounted on said standard, a pair of links operatively connecting said anvils to said plunger, a manually operable lever having one end pivotally mounted on said standard, and link operatively connecting said lever to said plunger.

2. In a retractable anvil stapling machine, a frame and operating mechanism supported by said frame, said operating mechanism comprising a standard mounted within said frame and cooperating therewith to provide a chamber, a plunger slidably mounted for vertical movement in said chamber, a staple driving blade carried by said plunger, a pair of retractable anvils each of which is pivotally mounted on said standard, a pair of links operatively connecting said anvils to said plunger, a manually operable lever having one end pivotally mounted on said standard, a link operatively connecting said lever to said plunger, and an adjustable abutment for limiting the vertical movement of said lever which causes the driving of said plunger.

3. In a retractable anvil stapling machine, a standard, a pair of retractable anvils rotatably mounted on said standard, a plunger reciprocally mounted in a guideway one side of which is defined by said standard, a staple driving blade carried by said plunger, a pair of links each having one end connected to said plunger and the other end connected to said anvils, a hand lever pivotally mounted on said standard, and a plunger link having one end pivotally mounted to the upper end of said plunger and its other end pivotally connected to said hand lever adjacent to the pivotal mounting thereof.

4. In a retractable anvil stapling machine, a standard, a pair of retractable anvils rotatably mounted on said standard, a plunger reciprocally mounted in a guideway one side of which is defined by said standard, a staple driving blade carried by said plunger, a pair of links each having one end connected to said plunger and the other end connected to said anvils, a hand lever having one end pivotally mounted for vertical movement on the upper end of said standard and formed with a depending ear adjacent to said pivotal mounting, a plunger link having one end pivotally connected to said ear and its other end pivotally connected to said plunger, and an abutment screw adjustably mounted in said standard and having a free end adapted to be engaged by said ear to limit the vertical movement of said hand lever.

5. In a retractabe anvil stapling machine, a frame including a front wall and operating mechanism supported by said frame and including a standard having a face in engagement with said front wall, said standard being formed with a transverse groove opening into the face engaging said wall, a block slidably mounted in said groove and having a central aperture, said front wall being formed with a circular opening the center of which is offset with respect to the midline of said groove, a cylindrical casing carried by said front wall and coaxial with the opening therein, a disc in said casing formed with a radial slot, an adjustinglever having an arm formed with a loop received in said slot and a free end received in said aperture, and means for retaining said loop assembled in the slot of said disc.

6. In a retractable anvil stapling machine, a frame including a front wall and operating mechanism supported 10 by said frame and including a standard having a face in engagement with said front wall, said standard being formed with a transverse groove opening into the face engaging said wall, a block slidably mounted in said groove and having a central aperture, said front wall being formed with a circular opening the center of which is oset with respect to the midline of said groove, a cylindrical casing carried by said front wall and coaxial with the opening therein, said casing being formed with a pair of openings in diametric alignment, a disc in said casing formed with a radial slot, and a diametric transverse passage normal to and crossing said slot, an adjusting lever having an arm formed with a loop received in said slot and a free end received in said aperture, a pin passing through said passage in the disc and the loop in the lever for maintaining said loop assembled in said disc, said pin being adapted to pass through the openings in said casing for disassembly purposes, said front Wall being formed with a series of openings over an arc concentric with said casing, and an inturned end portion on the end of said lever adapted to be received in any one of said openings.

7. In a stapling machine, a standard, a staple driving mechanism mounted on said standard and comprising a staple driving blade for engaging a U-shaped staple and driving it downwardly through the standard to project the staple legs through a material to be stapled, a pair of retractable anvils each of which is pivotally mounted on the standard for rocking movement, operating means for simultaneously moving said anvils and the driving blade in staple driving relationship through a connecting means between said anvils and blade, said connecting means being adapted to pivot the anvils and drive the blade simultaneously to project the said staple legs through the material and against said anvils, said pivotable movement of the anvils being continuous during the entire period that the movement of said blade first drives the staple legs against said anvils to the completion of the downward movement of said blade.

8. In a stapling machine, a standard, a staple driving mechanism mounted on said standard and comprising a staple driving blade for engaging a U-shaped staple and driving it downwardly through the standard to project the staple legs through a material to be stapled, a pair of retractable anvils each of which is pivotally mounted on the standard for rocking movement through an arc of approximately the anvils in retracted position having their ends directed vertically for downward movement to penetrate the work adjacent the lip of the staple, and pivotable from such position toward a horizontal position below the work and the staple, operating means for simultaneously moving said anvils and the driving blade in staple driving relationship, connecting means between said anvils and blade, said connecting means comprising a linkage pivotally connected directly to the blade and to said anvils to pivot the anvils and drive the blade simultaneously and to project the said staple legs through the material and against said anvils as the anvils move under the staple, said pivotable movement of the anvils being continuous during the entire period that the blade contacts the staple and drives the staple legs against said anvil, to

the completion of the downward movement of said blade.

References Cited in the le of this patent UNITED STATES PATENTS 1,878,417 Matveyett Sept. 20, 1932 2,055,257 Maynard Sept. 22, 1936 2,299,858 Sorenson Oct. 27, 1942 2,374,373 Nasmith Apr. 24, 1945 2,469,054 Schafroth May 3, 1949 2,469,055 Schafroth May 3, 1949 2,501,564 Goodstein Mar. 21, 1950 2,528,444 Marano Oct. 31, 1950 

